1 /* Copyright (c) 2016 Facebook 2 * 3 * This program is free software; you can redistribute it and/or 4 * modify it under the terms of version 2 of the GNU General Public 5 * License as published by the Free Software Foundation. 6 */ 7 #include <linux/ptrace.h> 8 #include <uapi/linux/bpf.h> 9 #include <uapi/linux/bpf_perf_event.h> 10 #include <uapi/linux/perf_event.h> 11 #include <bpf/bpf_helpers.h> 12 #include <bpf/bpf_tracing.h> 13 14 struct key_t { 15 char comm[TASK_COMM_LEN]; 16 u32 kernstack; 17 u32 userstack; 18 }; 19 20 struct { 21 __uint(type, BPF_MAP_TYPE_HASH); 22 __type(key, struct key_t); 23 __type(value, u64); 24 __uint(max_entries, 10000); 25 } counts SEC(".maps"); 26 27 struct { 28 __uint(type, BPF_MAP_TYPE_STACK_TRACE); 29 __uint(key_size, sizeof(u32)); 30 __uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64)); 31 __uint(max_entries, 10000); 32 } stackmap SEC(".maps"); 33 34 #define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP) 35 #define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK) 36 37 SEC("perf_event") 38 int bpf_prog1(struct bpf_perf_event_data *ctx) 39 { 40 char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu"; 41 char time_fmt2[] = "Get Time Failed, ErrCode: %d"; 42 char addr_fmt[] = "Address recorded on event: %llx"; 43 char fmt[] = "CPU-%d period %lld ip %llx"; 44 u32 cpu = bpf_get_smp_processor_id(); 45 struct bpf_perf_event_value value_buf; 46 struct key_t key; 47 u64 *val, one = 1; 48 int ret; 49 50 if (ctx->sample_period < 10000) 51 /* ignore warmup */ 52 return 0; 53 bpf_get_current_comm(&key.comm, sizeof(key.comm)); 54 key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS); 55 key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS); 56 if ((int)key.kernstack < 0 && (int)key.userstack < 0) { 57 bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period, 58 PT_REGS_IP(&ctx->regs)); 59 return 0; 60 } 61 62 ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value)); 63 if (!ret) 64 bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running); 65 else 66 bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret); 67 68 if (ctx->addr != 0) 69 bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr); 70 71 val = bpf_map_lookup_elem(&counts, &key); 72 if (val) 73 (*val)++; 74 else 75 bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST); 76 return 0; 77 } 78 79 char _license[] SEC("license") = "GPL"; 80